From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1N0dYb-0007TW-Ka for qemu-devel@nongnu.org; Wed, 21 Oct 2009 11:57:01 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1N0dYX-0007NY-L8 for qemu-devel@nongnu.org; Wed, 21 Oct 2009 11:57:01 -0400 Received: from [199.232.76.173] (port=47263 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1N0dYX-0007NE-G1 for qemu-devel@nongnu.org; Wed, 21 Oct 2009 11:56:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:62301) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1N0dYW-0004UT-UI for qemu-devel@nongnu.org; Wed, 21 Oct 2009 11:56:57 -0400 Received: from int-mx04.intmail.prod.int.phx2.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.17]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id n9LFuu1o005941 for ; Wed, 21 Oct 2009 11:56:56 -0400 Date: Wed, 21 Oct 2009 17:54:42 +0200 From: "Michael S. Tsirkin" Message-ID: <20091021155442.GA24932@redhat.com> References: <20091008203740.GA20727@redhat.com> <1256063981.27918.6.camel@blaa> <4ADE0809.2050500@redhat.com> <20091021154234.GA24913@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20091021154234.GA24913@redhat.com> Subject: [Qemu-devel] Re: [PATCH] qemu: work around for "posix-aio-compat" List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: Mark McLoughlin , qemu-devel@nongnu.org On Wed, Oct 21, 2009 at 05:42:34PM +0200, Michael S. Tsirkin wrote: > On Tue, Oct 20, 2009 at 08:57:13PM +0200, Paolo Bonzini wrote: > > On 10/20/2009 08:39 PM, Mark McLoughlin wrote: > >> On Thu, 2009-10-08 at 22:37 +0200, Michael S. Tsirkin wrote: > >>> With commit ee3993069ff55fa6f1c64daf1e09963e340db8e4, > >>> "posix-aio-compat: avoid signal race when spawning a thread" > >>> winxp installation on a raw format file fails > >>> during disk format, with a message "your > >>> disk may be damaged". > >>> > >>> This commit moved signal mask from aio thread to creating thread. > >>> It turns out if we keep the mask in aio thread as well, the problem > >>> disappears. It should not be needed, but since this is harmless, let's > >>> keep it around until someone inclined to debug pthread library internals > >>> can check this issue. > >>> > >>> While we are at it, convert sigprocmask to pthread_sigmask > >>> as per posix. > >> > >> FWIW, I just started hitting a boot hang with qemu.git and --enable-kvm > >> on a Fedora 11 machine with a Fedora 11 guest. > >> > >> I bisected it back to malc's commit, found this thread, applied > >> Michael's patch and confirmed that it fixes the problem for me too. > > > > If anybody can send me the output of compiling the "strange" file with > > and without the patch, both with "-fdump-tree-all -fdump-rtl-all -O2 > > --save-temps -g" flags, I could try debugging it in GCC. > > > > It will be huge, so bz/gz/lzip it. > > I've uploaded them here: > http://www.kernel.org/pub/linux/kernel/people/mst/ > you can't see them in mirrors yet but will be able to soon when > kernel.org mirroring system catches them. ok, it's there now: http://www.kernel.org/pub/linux/kernel/people/mst/posix-aio-corruption.tbz2 once you open this, you will see subdirectories "hang" and "nohang". the source file is also there, so that you can compare. > > > Paolo